The concentration of cesium in the earth's crust is understood to be approximately 3 ppm by weight. Economic ores of cesium are seldom found in nature, and may for example include the minerals analcime, cesium-thallium arsenic sulfosalts (thioarsenates), and cryptomelane group minerals. An economically important ore source mineral for caesium is pollucite (Cs(AlSi2O6)), but economic sources of pollucite are rarely found in nature. One such deposit is the Bernic Lake Deposit in Manitoba, Canada, which contains pollucite that has been mined and processed for cesium recovery. Processes for recovering cesium from a cesium ore such as pollucite are for example described in U.S. Pat. Nos. 2,808,313, 3,112,169, 3,207,571, 3,322,531, 4,597,955, 5,900,221, 7,323,150 and 9,045,812. The processing of cesium alums is for example discussed in U.S. Pat. Nos. 4,469,670, 6,015,535, 6,436,879, and 6,652,820.
The shortage of economic deposits of cesium has led to a long felt need for new sources of cesium to be identified.